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techgeek1987
12-05-2009, 04:00 AM
Im using the BS2 Homework Board, and i am wondering if there is a way to add an additional stamp controller to that board, using the stamp that is currently on it to control the additional stamp. if it is possible how would one go about doing it, or even the basic programming logic behind it?

Mike Green
12-05-2009, 04:57 AM
You could plug a Stamp module into the little breadboard area and power it using Vin and Vss on the Homework Board and the corresponding pins on the Stamp. You'd need to make a separate programming plug following the recommended schematic in the BASIC Stamp Syntax and Reference Manual.

Apart from the above, what do you mean by "control the additional stamp"? There are some examples in a two part article in Nuts and Volts on networking Stamps. Have a look at that. The index and links to the articles is available by going to Parallax's main webpage and clicking on the Resources tab. You'll see a link to the Nuts and Volts article index near the bottom of the Resources page.

techgeek1987
12-05-2009, 05:10 AM
Thank you for the reply. When I mentioned controlling the additional stamp.... I was asking, "can i use the BS2 stamp on the homework board to control the additional stamp that i plug in on the homework board?" (ex. I have a main stamp, that has slave stamps connected to it. the main stamp sends out codes to the slave stamps to tell them what to do)

Franklin
12-05-2009, 10:45 AM
techgeek1987 said...
·(ex. I have a main stamp, that has slave stamps connected to it. the main stamp sends out codes to the slave stamps to tell them what to do)
Yes, you can do that by talking between the stamps using SEROUT and SERIN or making pins high or low.

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- Stephen

Bill Chennault
12-06-2009, 07:04 AM
techgeek1987--

In the picture below, there are four OEM-BS2 boards controlled by a BS2p40. Communication was accomplished by raising pins high and then lowering them. Each of the five Stamps could be programmed either by a breadboarded RS232 interface (BS2p40) or a USB2SER (the BS2s).

The master/slave setup worked very well and made for some interesting programming. The programming was not complicated, in fact it was very simple because no single microcontroller had to do much. The advantage of not using the most-excellent SERIN/SEROUT commands is that you will never be waiting on one of the commands to complete. The disadvantage of using the master/slave setup is that it is obviously hardware heavy.

On the machine pictured below, I have replaced all of the microcontrollers with a single SX48 running at 20MHz.

http://www.billcnkc.com/Robotics/Ugly%20Buster/SS-10-29-07.jpg

[EDIT: Changed BS2px40 to BS2p40.]

--Bill

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You are what you write.

Post Edited (Bill Chennault) : 12/7/2009 1:45:26 AM GMT

$WMc%
12-06-2009, 11:55 PM
Bill Chennault

Nice BOT

I see you covered-up the wheel encoders, are they store bought or home made?

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The Truth is out there············___$WMc%___······················ ······ BoogerWoods, FL. USA

Bill Chennault
12-07-2009, 01:31 AM
$WMc%--

You USED to be able to buy them as an option at Banebot (http://banebots.com/osc/support/gearmotor_comp.htm). However, that is no longer possible. But, when it was, they came fully calibrated as part of the gearbox.

After I run out of the old Banebot motors with built-in encoders, I will start building my own. (Banebot still has an incredibly interesting line of gearmotors. Think dual motors driving a single gearbox.)

--Bill



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You are what you write.

Julie in Texas
12-07-2009, 11:38 PM
The next time you need to do asynchronous master / slave control, use a pair of latches to construct a mailbox setup. You could use some sort of serial to parallel shift register chip (brain is rusty on 74xx parts, so no number for you) as the data output. Toggle a flip-flop "high" when there is data to be read. The slave polls the flip-flop to see if it has data from the master, then reads the I/O pins to get the data, and toggles the flip-flop "low".

It completely breaks up the SEROUT / SERIN synchronization problem without adding too many parts.